Extract some code to separate function
Goals include:
- reducing the number of local variables in the main function (so that we
don't have to worry about saving/restoring them)
- reducing the number exit points in the main function, making it easier to
update ssl->state only right before we return
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 48bb336..f91e2a8 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -4309,62 +4309,16 @@
return( ret );
}
-int mbedtls_ssl_parse_certificate( mbedtls_ssl_context *ssl )
+/*
+ * Once the certificate message is read, parse it into a cert chain and
+ * perform basic checks, but leave actual verification to the caller
+ */
+static int ssl_parse_certificate_chain( mbedtls_ssl_context *ssl )
{
- int ret = MBEDTLS_ERR_SSL_FEATURE_UNAVAILABLE;
+ int ret;
size_t i, n;
- const mbedtls_ssl_ciphersuite_t * const ciphersuite_info =
- ssl->transform_negotiate->ciphersuite_info;
-#if defined(MBEDTLS_SSL_SRV_C) && defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
- const int authmode = ssl->handshake->sni_authmode != MBEDTLS_SSL_VERIFY_UNSET
- ? ssl->handshake->sni_authmode
- : ssl->conf->authmode;
-#else
- const int authmode = ssl->conf->authmode;
-#endif
uint8_t alert;
- MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse certificate" ) );
-
- if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK ||
- ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK ||
- ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK ||
- ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE )
- {
- MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate" ) );
- ssl->state++;
- return( 0 );
- }
-
-#if defined(MBEDTLS_SSL_SRV_C)
- if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER &&
- ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK )
- {
- MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate" ) );
- ssl->state++;
- return( 0 );
- }
-
- if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER &&
- authmode == MBEDTLS_SSL_VERIFY_NONE )
- {
- ssl->session_negotiate->verify_result = MBEDTLS_X509_BADCERT_SKIP_VERIFY;
- MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate" ) );
- ssl->state++;
- return( 0 );
- }
-#endif
-
- if( ( ret = mbedtls_ssl_read_record( ssl ) ) != 0 )
- {
- /* mbedtls_ssl_read_record may have sent an alert already. We
- let it decide whether to alert. */
- MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret );
- return( ret );
- }
-
- ssl->state++;
-
#if defined(MBEDTLS_SSL_SRV_C)
#if defined(MBEDTLS_SSL_PROTO_SSL3)
/*
@@ -4384,10 +4338,7 @@
one. The client should know what's going on, so we
don't send an alert. */
ssl->session_negotiate->verify_result = MBEDTLS_X509_BADCERT_MISSING;
- if( authmode == MBEDTLS_SSL_VERIFY_OPTIONAL )
- return( 0 );
- else
- return( MBEDTLS_ERR_SSL_NO_CLIENT_CERTIFICATE );
+ return( MBEDTLS_ERR_SSL_NO_CLIENT_CERTIFICATE );
}
}
#endif /* MBEDTLS_SSL_PROTO_SSL3 */
@@ -4408,10 +4359,7 @@
one. The client should know what's going on, so we
don't send an alert. */
ssl->session_negotiate->verify_result = MBEDTLS_X509_BADCERT_MISSING;
- if( authmode == MBEDTLS_SSL_VERIFY_OPTIONAL )
- return( 0 );
- else
- return( MBEDTLS_ERR_SSL_NO_CLIENT_CERTIFICATE );
+ return( MBEDTLS_ERR_SSL_NO_CLIENT_CERTIFICATE );
}
}
#endif /* MBEDTLS_SSL_PROTO_TLS1 || MBEDTLS_SSL_PROTO_TLS1_1 || \
@@ -4555,6 +4503,75 @@
}
#endif /* MBEDTLS_SSL_RENEGOTIATION && MBEDTLS_SSL_CLI_C */
+ return( 0 );
+}
+
+int mbedtls_ssl_parse_certificate( mbedtls_ssl_context *ssl )
+{
+ int ret;
+ const mbedtls_ssl_ciphersuite_t * const ciphersuite_info =
+ ssl->transform_negotiate->ciphersuite_info;
+#if defined(MBEDTLS_SSL_SRV_C) && defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
+ const int authmode = ssl->handshake->sni_authmode != MBEDTLS_SSL_VERIFY_UNSET
+ ? ssl->handshake->sni_authmode
+ : ssl->conf->authmode;
+#else
+ const int authmode = ssl->conf->authmode;
+#endif
+
+ MBEDTLS_SSL_DEBUG_MSG( 2, ( "=> parse certificate" ) );
+
+ if( ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_PSK ||
+ ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_DHE_PSK ||
+ ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECDHE_PSK ||
+ ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_ECJPAKE )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate" ) );
+ ssl->state++;
+ return( 0 );
+ }
+
+#if defined(MBEDTLS_SSL_SRV_C)
+ if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER &&
+ ciphersuite_info->key_exchange == MBEDTLS_KEY_EXCHANGE_RSA_PSK )
+ {
+ MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate" ) );
+ ssl->state++;
+ return( 0 );
+ }
+
+ if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER &&
+ authmode == MBEDTLS_SSL_VERIFY_NONE )
+ {
+ ssl->session_negotiate->verify_result = MBEDTLS_X509_BADCERT_SKIP_VERIFY;
+ MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= skip parse certificate" ) );
+ ssl->state++;
+ return( 0 );
+ }
+#endif
+
+ if( ( ret = mbedtls_ssl_read_record( ssl ) ) != 0 )
+ {
+ /* mbedtls_ssl_read_record may have sent an alert already. We
+ let it decide whether to alert. */
+ MBEDTLS_SSL_DEBUG_RET( 1, "mbedtls_ssl_read_record", ret );
+ return( ret );
+ }
+
+ if( ( ret = ssl_parse_certificate_chain( ssl ) ) != 0 )
+ {
+#if defined(MBEDTLS_SSL_SRV_C)
+ if( ret == MBEDTLS_ERR_SSL_NO_CLIENT_CERTIFICATE &&
+ authmode == MBEDTLS_SSL_VERIFY_OPTIONAL )
+ {
+ ret = 0;
+ }
+#endif
+
+ ssl->state++;
+ return( ret );
+ }
+
if( authmode != MBEDTLS_SSL_VERIFY_NONE )
{
mbedtls_x509_crt *ca_chain;
@@ -4641,6 +4658,8 @@
if( ret != 0 )
{
+ uint8_t alert;
+
/* The certificate may have been rejected for several reasons.
Pick one and send the corresponding alert. Which alert to send
may be a subject of debate in some cases. */
@@ -4683,6 +4702,8 @@
#endif /* MBEDTLS_DEBUG_C */
}
+ ssl->state++;
+
MBEDTLS_SSL_DEBUG_MSG( 2, ( "<= parse certificate" ) );
return( ret );